From the verb phrase blow off.
blowoff (plural blowoffs)
- Something that is blown off.
- The explosive separation of part of a rocket etc in order to prevent its destruction and allow for retrieval
- A blowing off of steam, water, etc.
- (colloquial) An outburst of temper or excitement.
- (Britain, slang) A fart.
Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.
(See the entry for blowoff in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.)