The bulk update request #4232 is pending approval.
create alias white_underside (27) -> white_countershading (19992)
create alias foot_growth (15) -> foot_expansion (224)
create alias butt_growth (6) -> butt_expansion (5225)
create alias laughs (2) -> laugh (12358)
Reason: As the title implies, they have an identical meaning.
Also of note, I picked the smaller tag to alias from and the bigger tag to alias to.