I. adverb 1. completely; totally • I stopped seeing her altogether
• [as submodifier]
I’m not altogether sure that I’d trust him.
2. including everything or everyone; in total • he had married several times and had forty-six children altogether.
3. [ sentence adverb] — taking everything into consideration; on the whole • altogether it was a great evening.
II. phrases in the altogether
‹informal› without any clothes on; naked.
• she’s agreed to pose in the altogether.
– origin Old English (see all, together). / usage: Note that altogether and all together do not mean the same thing. Altogether means ‘in total’, as in there are six bedrooms altogether, whereas all together means ‘all in one place’ or ‘all at once’, as in it was good to have a group of friends all together; they came in all together.