[KozmoNau7]

I considered that term, but the ones I like the most are made from heavyweight cotton twill, similar in weight to denim but with a different weave and feel. Whereas I think combat pants are generally some sort of polycotton or cordura ripstop fabric.

So it's "service" as in service tech or mechanic, not military service.

[funnybeam]

Another UK commenter - over here that cotton twill is known as moleskin and a lot of the army surplus is in that fabric which I agree is much nicer than the ripstop stuff