μήγε [7 verses](particle) "Not" is mege, which is a contraction of me ge. The me is the negative used in prohibitions and expressions of doubt meaning "not" and "no." The ge is an emphatic particle meaning "at least" and "indeed." It emphasizes the word to which it is associated. --  "Not at all"  is the negative used in opinions, prohibitions, possibilities, and expressions of doubt meaning "not" and "no" with an emphatic particle meaning "at least" and "indeed." So the sense is "no indeed."

μείζων [22 verses](adj sg masc nom comp ) "Greater" is meizon which means "bigger," "higher," "longer," and "greater" and is the comparative form of megas, which means "big" and "great." The superlative form "greatest" is megistos, μέγιστος. The superlative form "greatest" is megistos, μέγιστος. -- "Greatest" is an adjective which is the comparative form of the word meaning "big" or "great." It means "bigger," "higher," "longer," "greater" and simply, "superior." When it is introduced by an article, it means "the greater." It is not the superlative form.

μηκέτι [4 verses](adv) "Henceforward" is meketi, which means "no more," "no longer," and "no further."  - The word translated as "henceforth" means "no longer." It expresses an opinion. However, in Greek, the double negative doesn't make a positive, like it does in English so when used with a negative, "anymore" works better. 

μηκύνηται [1 verse]( verb 3rd sg fut ind mid or verb 3rd sg pres subj mp or verb 3rd sg aor subj mid ) "Grow up" is from mekuno, which means "to lengthen," "to make long," "to prolong," "to grow tedious," "stretch out a syllable," and "to multiply by some factor."  - "Grow up" is from a unique verb for Jesus to us. It means "to lengthen," "to make long," "to prolong," "to grow tedious," "stretch out a syllable," and "to multiply by some factor." The meaning of "to lengthen," if a bit of word play, where Jesus describes what he is doing in the story by using a long of "ands." It also means "to multiply by some factor," which is the likely meaning here given the context. The tense of this verb, which seems odd because the man is described in the present. However, in the alternative, you can see how it words that way, giving a sense that time passed in the "day" and "night" section.

() "Black" is melas, which means "black", "dark", "murky", "swarthy", "indistinct [of a voice]", "obscure", "enigmatic," and "malignant [of character]."