ثِلْثٌ

The third young one or offspring, (M, A, K,) of a she-camel, (M, K,) and, accord, to Th, of any female: (M:) and in like manner others are termed, to ten [inclusive]. (A.) But one should not say نَاقَةٌ ثِلْثٌ [after the manner of ثِنْىٌ, q. v.]. (M.)

سَقَى نَخْلَهُ الثِّلْثَ He watered his palm-trees once in three days: (A:) or he watered them بَعْدَ الثُّنْيَا [which apparently means after excepting, or omitting, one day]. (K.) ثِلْثٌ is not used [thus] except in this case: there is no ثِلْث in the watering of camels; for the shortest period of watering is the رِفْه when the camels drink every day; then is the غِبّ, which is when they come to the water one day and not the next day; and next after this is the رِبْع; then, the خِمْس; and so on to the عِشْر: so says As: (S, TA:) and this is correct, though J's assertion that ثِلْث is not used except in this case is said by F to require consideration. (TA.)

حُمَّى الثِّلْثِ i. q. حُمَّى الغِبِّ, [The tertian fever;] the fever that attacks one day and intermits one day and attacks again on the third day; called by the vulgar ↓ المُثَلِّثَةُ. (Msb.)