1. A child born out of wedlock.
2. Something that is of irregular, inferior, or dubious origin.
3. Slang. A person, especially one who is held to be mean or disagreeable.

1. Born of unwed parents; illegitimate.
2. Not genuine; spurious: a bastard style of architecture.
3. Resembling a known kind or species but not truly such.

[Middle English, from Old French, probably of Germanic origin, akin to Old Frisian bōst, marriage.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.