فلنفُلَانٌ is a substitute for the proper name of a human being, (S, Msb, * K, TA,) i. e. of a male; (S, TA;) and in like manner ↓ فُلَانَةُ, (Msb, K, TA,) for that of a female; (TA,) each without ال; (Msb:) [the former may be rendered Such a one, or Such a man; and the latter, Such a woman:] and الفُلَانُ and ↓ الفُلَانَةُ for other than a human being, (S, K, TA,) i. e. for a [particular] camel, (Lth, TA,) or for a [particular] beast, as in the saying, رَكِبْتُ الفُلَانَ [I rode such a beast, i. e. such a male beast], and ↓ حَلَبْتُ الفُلَانَةَ [I milked such a beast]: (Msb, TA:) فُلَانٌ has  no dual nor pl.: (IB, TA:) [but] sometimes one says to a single person, mase., يَا فُلُ; and to two, يَا فُلَانِ; and to a pl. number, يَافُلُونَ: and in the fem., يَا فُلَةُ; &c.; (K: [see more in art. فل:]) accord. to Kh, فُلَانٌ is of the measure فُعَالٌ; and its dim. is ↓ فُلَيْنٌ: (TA:) or, as some say, it is of the measure فُلَانٌ, [originally فُلْوَانٌ,] with و rejected, therefore its dim. is ↓ فُلَيَّانٌ [originally فُلَيْوَانٌ]; (T, L, TA;) like as إنْسَانٌ is [said by some to be] إنْسِيَانٌ, of which the ى is rejected. and therefore its dim. is أُنيْسِيَانٌ. (T, L.) فُلِيْنٌ: see the preceding paragraph.فُلَانَةُ, and الفُلَانَةُ: see فُلَانٌ, in three places.فُلَانِىٌّ the rel. n. of فُلَانٌ: it is rendered indeterminate by the affix ى; and by means of the article اَلْ, it becomes determinate; therefore  you say فُلَانٌ الفُلَانِىُّ [meaning Such a one, the person named in relation to such a one], (TA,) فُلَيَّانٌ: see فُلَانٌ, near the end.