The argument is that they're called triples even when they've got more or less components than 3. They should have simply been called target tuples or target monikers.
"gnu tuple" and "gnu type" are also common names.
The comments in `config.guess` and `config.sub`, which are the origin of triples, use a large variety of terms, at least the following:
configuration name
configuration type
[machine] specification
system name
triplet
tuple