What is the meaning of Ni-?

A terminative prefix referring to stopping or termination of an action, or performing an action up to a point.

Carries several extended meanings, which possibly are the result of conflation with other prefixes:

1. embedding into
2. hanging over, up and over
3. up vertically
4. off from shore
5. off of, undressing

embedding into

hanging over, up and over

up vertically

off from shore

off of, undressing

Subject prefix for verbs; indicates that the subject is first person singular: I.

look at

I (used for conjugating verbs to the subjective or nominative case of the personal pronoun)

pronominal prefix for

partitive prefix

used to form the days of the week

uninterrupted, intensely

very, a lot

Used as an intensifier, especially in verbs

A prefix denoting the first person

new-, newly

down

I, first-person singular subject marker.

you, you all; second-person plural subject concord.

you, you all; second-person plural object concord.

second-person plural clitic, you all

second-person singular possessive pronoun, your

A thematic prefix or pair of homophonous thematic prefixes with the following meanings:

1. Relates to tactile descriptive qualities.
2. Relates to the mind and feelings.

Relates to tactile descriptive qualities.

Relates to the mind and feelings.

Marks a second person singular possessor of a noun or object of a postposition.

second-person singular possessive prefix, your

alternative form of na- (“our (inclusive)”) when preceded by a root-initial i

1st person singular subject concord.

Allomorph of n- (third-person prefix) used for stems that begin with a consonant.

With following vowel lengthened if in an unreduced open syllable.

un-; de- (used to negate)

alternative form of ming-

no

Marks a noun as being have a second-person singular possessor

Marks a postposition as having a second-person singular object

Marks a verb as having a second-person singular subject

Marks a verb as belonging to the ni-imperfective paradigm, which contains verbs confined to the momentaneous aspect.

Marks a verb as belonging to the terminative subaspect, marking the cessation or end of an action or the reaching of a goal.

Forms neuter imperfective/adjectival verbs

Marks the ni-perfective paradigm, which connotes an action that was terminal or finished

A thematic prefix

Prefix prepended to pronouns to denote a negative meaning, synonymous with ne- (“no, not”).

Prefix prepended to copula verb biti in present tense to denote a negative meaning, synonymous with ne- (“not”).

I, 1st person singular subject concord

verb-initial form of -ni- (“me, 1st person singular object concord”)

alternative form of -in-

1st person singular subject concord, I

nasal mutation of di-

you, you all; second-person plural subject concord.

you, you all; second-person plural object concord.

you, you all; second-person plural subject concord.

you, you all; second-person plural object concord.

Source: wiktionary.org