Darn it, got me again today with 'rapids'. Click the definition = pural of rapid.
I don't think I'm even going to get my head(s) around this. (I can say heads plural, I'm from Tasmania
)
That just got me thinking, when tossing a coin we call 'heads' or 'tails', so would not they be permissible plurals?
Is it the same as tricep/triceps? And for that matter bicep/biceps? I've always thought that biceps and triceps were singular nouns and that bicep and tricep were actually popular misnomers because people assume that biceps and triceps are plurals.
Thank you for that, I've been caught out trying to play 'tricep' before. Your explanation reminded me these are groups of muscles.