pronoun (demonstrative) (plural those)
1. (used to indicate a person, thing, idea, etc., as pointed out or present, or as before mentioned or supposed to be understood, or as about to be mentioned, or by way of emphasis): that's my choice.
2. (used to indicate the one of two or more persons, things, etc., already mentioned, that is more remote in place, time, or thought.)
3. (used to indicate one of two or more persons, things, etc., already mentioned, implying contradistinction (opposed to this).)
–pronoun (relative) 4. (used as the subject or object of a relative clause, especially one defining or restricting the antecedent, sometimes replaceable by who, whom, or which): the man that arrived; the man that I saw.
5. (used as the object of a preposition, the preposition being at the end of the relative clause): the man that I spoke of.
6. (used in various special or elliptical constructions): fool that he is.
–adjective (demonstrative) (plural those)
7. (used to indicate a person, place, thing, idea, etc., as pointed out or present, as before mentioned or supposed to be understood, or by way of emphasis): we want that help especially.
8. (used to indicate, of two or more persons, things, etc., already mentioned, the one more remote in place, time, or thought.)
9. (used to indicate one of two or more persons, things, etc., already mentioned, implying contradistinction (opposed to this).)
–adverb 10. (used with adjectives and adverbs of quantity or extent to indicate precise degree or extent): that much; that far.
11. Colloquial (used with other adjectives and adverbs to indicate extent or degree, or for emphasis): poor lad, he was that weak!
–conjunction 12. (used to introduce a clause as the subject or object of the principal verb or as the necessary complement to a statement made, or a clause expressing cause or reason, purpose or aim, result or consequence, etc.): that he will come is certain; I know that you will do it.
13. (used elliptically, to introduce a sentence or clause expressing desire, surprise, or indignation): that you could do such a thing!
–phrase 14. and (all) that, Colloquial and other related items: the drawer was full of pencils and that.
15. at that, additionally; besides: it's an idea, and a good one at that.
16. be all that, Colloquial to be extremely attractive or stylish.
18. that is, more precisely (in clarification or example).
19. that said, in spite of what has just been uttered; nevertheless.
20. that's that, that is the end of the matter; the matter is closed or finished (used dismissively).
21. that there …, (a jocular adoption of a non-standard form): pass me that there book.
22. with that, thereupon; immediately afterwards: *`Come! off with them!' and with that I snapped the laces of his balmorals; for he had sunk to the ground –joseph furphy, 1903.[Middle English; Old English thæt that, the]
Usage: In traditional grammar, that has been used to begin a restrictive clause, and which a non-restrictive or descriptive clause. This distinction is falling out of use.