The externals are the outer look of a situation — what you can see from the outside, not the real inside story. Clothes, smiles, a tidy room, a polite report, a new shop sign. People say you should not go by the externals when the surface is lying, or at least not the whole truth. The word is almost always plural in this meaning; it names the shell, not one single outer thing. Fairly formal. Though actually, in easy talk most people just say “the outside” or “appearances,” and they are pointing at the same gap: what it looks like versus what it is. Older, more bookish speakers like externals; younger speakers can live their whole lives without it.

外表；外在表象