this

American Heritage® Dictionary of the English Language, Fourth Edition

1. pro. Used to refer to the person or thing present, nearby, or just mentioned: This is my cat. These are my tools.
2. pro. Used to refer to what is about to be said: Now don't laugh when you hear this.
3. pro. Used to refer to the present event, action, or time: said he'd be back before this.
4. pro. Used to indicate the nearer or the more immediate one: This is mine and that is yours.
5. adj. Being just mentioned or present in space, time, or thought: She left early this morning.
6. adj. Being nearer or more immediate: this side and that side.
7. adj. Being about to be stated or described: Just wait till you hear this story.
8. adj. Informal Used as an emphatic substitute for the indefinite article: looking for this book of recipes.
9. adv. To this extent; so: never stayed out this late.

Century Dictionary and Cyclopedia

1. That is now present or at hand: a demonstrative adjective used to point out with particularity a person or thing that is present in place or in thought. It denotes— Some person or thing that is present or near in place or time, or is nearer in place or time than some other person or thing, or has just been mentioned or referred to, and is therefore opposed to or the correlative of that: as, this city was founded five hundred years ago, or one hundred years earlier than that (city); this day; this time of night; these words.
2. Time just past or just at hand; the last or the next. The reference, whether to past or to future, is determined by the circumstances; this evening may mean either the evening now approaching, or next to come, or the evening now present, or the evening just past: as, it has occurred twice this year; I shall take care not to fail this (next) time. In this connection this is sometimes used for these, the sum being reckoned up, as it were, in a total.
3. This person or thing. It denotes—Some person or thing actually present or at hand: as, is this your coat? Who is this?
4. Something that has just preceded or has been mentioned or referred to.
5. Emphatically, something that is to be immediately said or done: as, Let me tell you this: I shall lend you no more money.
6. Elliptically, this person, place, state, time, position, circumstance, or the like: as, I shall leave this [place or town] to-morrow; this [state of affairs] is very sad; I shall abstain from wine from this [time] on; by this [time] we had arrived at the house.
7. When opposed to that, this refers to the person or thing that is nearer, that to the person or thing that is more distant; so, with things that have just been expressed, this refers to the thing last mentioned (and therefore nearer in time to the speaker), and that to the thing first mentioned (as being more remote).
8. For this; thus.

Wiktionary

1. The (thing) here (used in indicating something or someone nearby).
2. The known (thing) (used in indicating something or someone just mentioned).
3. The known (thing) (used in indicating something or someone about to be mentioned).
4. A known (thing) (used in first mentioning a person or thing that the speaker does not think is known to the audience). Compare with "a certain ...".
5. adv. To the degree or extent indicated.
6. pro. The thing, item, etc. being indicated.
7. n. philosophy Something being indicated that is here; one of these.
8. interj. Internet slang Indicates the speaker's strong approval or agreement with the previous material.

GNU Webster's 1913

1. prep. As a demonstrative pronoun, this denotes something that is present or near in place or time, or something just mentioned, or that is just about to be mentioned.
2. prep. As an adjective, this has the same demonstrative force as the pronoun, but is followed by a noun.