Inappropriate (adjective)

1. Not suitable or fitting for a particular purpose, occasion, or situation.
2. Not appropriate in a particular context.

Origin:

Mid 17th century: from in- "not" + appropriate, on the pattern of latin inappropriatus.

Examples:

1. The behavior was inappropriate.
2. The comment was inappropriate.
3. The attire was inappropriate.
4. The timing was inappropriate.
5. The joke was inappropriate.