adverb
at that time :at the time mentioned
a - used to indicate what happened or happens next
b - used to indicate what should be done next
c - used to indicate something more that must be done or thought of
a - used to indicate what must be true or what must or should happen if something else is true or happens
Then is often omitted following if.
b - used to say or ask about what appears to be true based on what has happened or been said
c - used to say what has been agreed to or decided
d somewhat formal - used to make a final statement that refers back to the things that have just been mentioned or described
used after words like all right and OK at the beginning of a statement
and then some
but then
even then
(every) now and then
then and there
or chiefly Brit there and then
immediately at that place
noun
[singular] :that time
adjective
always used before a noun
existing at or belonging to the time mentioned