Real Dictionary

t.o. in American English
abbreviation: telegraph office
abbreviation: turnover

to in American English
adverb: toward a point, person, place, or thing, implied or understood
preposition: (used for expressing motion or direction toward a point, person, place, or thing approached and reached, as opposed to from)

to in American English 1
in the direction of; toward

to in American English 2
turnover

to in British English 1
adverb: towards a fixed position, esp (of a door) closed
preposition: used to indicate the destination of the subject or object of an action

to in British English 2
the internet domain name for: Tonga

to preposition and adverb uses
preposition: You use to when indicating the place that someone or something visits, moves towards, or points at.

to used before the base form of a verb
You use to before the base form of a verb to form the to-infinitive. You use the to-infinitive after certain verbs, nouns, and adjectives, and after words such as 'how', 'which', and 'where'.

to- in American English
completely, entirely, severely