To those who have some but little familiarity with philosophy and those who have none at all should understand that attempting to find a definition for philosophy is a somewhat difficult thing to do. Not to say that it makes our task complicated and tedious, but rather we must be careful so that philosophy can be understood somewhat characteristically and distinctively apart from other disciplines of knowledge. So, for instance, consider a statement from British philosopher Roger Scruton on this issue: “What is Philosophy? There is no simple answer to this question: it is one respect the main question of philosophy, whose history is a prolonged search for its own definition.” 
Of course, philosophy at times has been defined in contrast to other disciplines (mathematics, science, etc.) and defined as to what philosophy is not. For instance, it has been said that philosophy differs from science in that it does not rely on experiments and/or observation, but rather on thought. Similarly, philosophy also differs from mathematics in that it does not have any formal methods of “proof.” On this point, consider philosopher Thomas Nagel’s treatment of philosophy with respect to the questions that other disciplines raise:
A historian may ask what happened at some time in the past, but a philosopher will ask, “What is time?” A mathematician may investigate the relations among numbers, but a philosophy will ask, “What is a number?” A physicist will ask what atoms are made of or what explains gravity, but a philosopher will ask how we can know anything outside of our own minds. A psychologist may investigated how children learn a language, but a philosopher will ask, “What makes a word mean anything? 
Hence, in a lot of ways the average non-philosopher can ask questions (and indeed, in many ways already has) that have philosophical interest. For instance, questions of what really exists, whether there is really anything that is right or wrong, whether life has meaning, whether there is life after death, and so on. However, though we may be developed in our analytical capacities in this way, the task of philosophy, or the disciplinary focus of philosophy, is sometimes what may allude us in terms of our practice of rationality on these questions.
So then, what can we really say about philosophy? Well, in its definitive essence, philosophy is “the love of wisdom” or “friendship” (philia) with wisdom (sophia). Philosophy, as Peter Kreeft understands the term, is one who loves truth of a certain kind. As he writes, “Wisdom is more than knowledge. Knowing all the facts in a library does not make you wise. Wisdom is a knowledge not just of facts but of values, of what is humanly important; and it is a knowledge that is lived, that is learned by experience and lived out in experience” .
This is respectively true once you examine the understanding of the discipline of philosophy through the thought of Socrates, Plato (who was the student of Socrates) and Aristotle (who was the student of Plato). For instance, in his treatise on metaphysics Aristotle begins by asserting that all human beings have the natural desire to acquire knowledge. However, what Aristotle meant by this was the pursuit of knowledge for its own sake, and not necessarily from its mere utility. For instance, as philosopher Stanley Rosen comments, “Aristotle cites the delight that we take in sense perception, and in particular, in vision, the sense that discriminates the largest number of intelligible forms” .
This “delight in vision” is one his teacher Plato expresses in his Symposium, where he attributes it to a demonic force, named Eros, who raises human beings up from the world of everyday life to the domain of “pure intelligible structure” . In these two instances from the “founding fathers of the Western philosophical tradition,” we can see on the one hand a poetical and a prosaic statement on the other about the universality of philosophical love. Although Plato expounds on this sort of “philosophical vision” of our experience, there is also another central question to the attention of Plato that must considered: “What kinds of knowledge is characteristically philosophical?”
This question is one that sits very comfortably even today in contemporary discussions about philosophy. However, I think that answer is best understood once we re-visit the conversation of philosophy with respect to other disciplines – namely, that philosophy can be distinctively understood once characterized apart from other disciplines of knowledge such as science, theology, mathematics, and etc. Take scientific knowledge as an example. If taken upon close and proper scrutiny, we see that scientific knowledge cannot be explained in purely theoretical terms; in the sense that the propositions which describe “the state of things” are themselves dependent upon a host of other assumptions about scientific procedure which cannot themselves be verified by that very procedure.
As Rosen explains, “[S]cience is saturated philosophy in the form of theories about how to conduct the scientific enterprise, in particular about what things are, and how they become, accessible to scientific investigation” . Thus, in a way, it would be right to say that science has some sort of a philosophical pretext so as to develop its “procedural function.”
To summarize what has been said here, philosophy can be understood in the definitional sense as “the love of wisdom,” so say to say that a philosopher has more of a concern not so much with knowledge itself but also with wisdom and truth. Furthermore, that philosophy is also a sort of procedural discipline that can help us analyze concepts, ask questions about ourselves and the reality which we are apart of, and help us better structure our “analytical capacities.” For further introductory material on this subject, see the “suggested readings” section at the very bottom of the post.
-  Roger Scruton, Modern Philosophy (Penguin Books: 1996) p. 3
-  Thomas Nagel, What Does it All Mean? (Oxford University Press: 1987) p. 5
-  Peter Kreeft, Philosophy 101 by Socrates (Ignatius Press: 2002) pp. 9-10
-  Stanley Rosen, The Philosophers Handbook (Random House: 2000) Introduction. xiii.
-  Ibid.
-  Ibid., xiv.
- Norman Geisler and Paul Feinberg, An Introduction to Philosophy: A Christian Perspective (Backer Books: 1980)
- The Philosopher’s Handbook: Essential Readings from Plato to Kant, ed. Stanley Rosen (Random House: 2000)
- Peter Kreeft, Philosophy 101 by Socrates (Ignatius Press: 2002)
- Thomas Nagel, What Does it All Mean? A Very Short Introduction to Philosophy (Oxford University Press: 1987)
- C. C. W. Taylor, R.M. Hare and Jonathan Barnes, Greek Philosophers (Oxford University Press: 1999)
- Eric A. Havelock, Preface to Plato (Harvard University Press: 1963)