A question, an inquiry (US), an enquiry (UK).
The teacher answered the student’s query concerning biosynthesis.
A question mark.
A set of instructions passed to a database.
The database admin switched on query logging for debugging purposes.
To ask a question.
To ask, inquire.
To question or call into doubt.
To pass a set of instructions to a database to retrieve information from it.
To send a private message to (a user on IRC).
To send out a query letter.