Lexical Definition

‎πλεῖστος‎ pleîstos (plice'-tos) most ^G:A
irregular superlative of ‎πολύς‎

very great, most.

• the largest number or very large

Abbott-Smith

πλεῖστος, πλείων, v.s. πολύς.

Liddell-Scott-Jones

πλεῖστος, η, ον,

superlative of πολύς, most, greatest, largest, in number, size, extent, etc., π. ὅμιλος, λαός, [Refs 8th c.BC+]most in vogue, [Refs 5th c.BC+]; τῇ γνώμῃ πλεῖστός εἰμι, ἡ π. γνώμη, [Refs 5th c.BC+]; πλεῖστον σχήσειν, as superlative of πλέον ἔχειν (see. πλείων), [Refs 5th c.BC+]

__2 with Article, οἱ π. the greatest number, [Refs]; τὸ π. τοῦ βίου the greatest part of.., [Refs 5th c.BC+]
__II Special usages: with relative, ὅσας ἂν πλείστας δύνωνται καταστρέφεσθαι subdue the greatest number that they possibly could, [Refs 5th c.BC+]; ὅς κα πλεῖστον διδῷ ἀποδόμενοι [Refs 5th c.BC+]
__III adverb usages: πλεῖστον most, [Refs 8th c.BC+]: sometimes added to a superlative, π. ἐχθίστη [Refs 5th c.BC+] as adverb, [Refs 5th c.BC+]; π. χαίρειν, frequently in letters, [Refs 1st c.BC+]
__III.b furthest, π. ἀφεστηκέναι [Refs 5th c.BC+]
__III.2 with Article, τὸ π. at most, ἡμερῶν τεσσάρων τὸ π. [Refs 5th c.BC+]for the most part, [Refs 5th c.BC+]; opposed to ἐνίοτε, [Refs 5th c.BC+]
__IV with Preps.:
__IV.1 διὰ πλείστου furthest off, in point of space or time, [Refs 5th c.BC+]
__IV.2 ἐς πλεῖστον most, [Refs 5th c.BC+]
__IV.3 ἐπὶ πλεῖστον over the greatest distance, to the greatest extent, in point of space, time, or extent, ἐπὶ π. χλιδῆς ἀπίκετο [Refs 5th c.BC+]; ὡς ἐπὶ π. or ὡς ἐπὶ τὸ π., for the most part, [Refs 5th c.BC+]
__IV.4 κατὰ τὸ π. for the most part, [Refs 2nd c.BC+]
__IV.5 περὶ πλείστου ποιεῖσθαι, see at {περί} [Refs 4th c.BC+]
__IV.6 ἐν τοῖς πλεῖσται, see ὁ, ἡ, τό, [Refs 4th c.BC+]