Since this thread seems mostly to be about defining terms, I'll throw my muddy two cents in!
... Like in fencing a "block" can be a pary, a deflection, where you with angled movement and little effort redirect/deflect the strike away from you ...
A block is a block, a strike is a strike and sometimes (not always) a block is a strike and a strike is a block and a strike : )
I block is, at the very basic, denotation level, something where you use one force to impede the motion of a primary force, thus causing it to NOT impact it's primary target. I would guess that most of us, at our more etymological and philosophical will distuinguish, somewhere in the vicinity of five levels of strike-negation.
1. Strike the Strike. These are the aggressive, smashing "blocks" meant to inflict damage to the opponents strike. I'm thinking of iron monkey type smashy-smashy, as in, "hey, you threw an instep kick at my thigh, so I'll smash it with my knee-cap.
2. Block the Strike. These are, I would say, the truest "blocks" in the dictionary denotation of the term. You just put something in between the target and the incoming strike and hope it mostly stops the impact, for example, covering the side of your head with a folded arm to avoid getting your ear mashed by a hay-maker.
3. Redirect the Strike. These are the strike-negations that make contact, but, rather than trying to stop or diminish the incoming force, they merely stear it away from anything dangerous.
4. Muting the Strike. The negations where you get hit, but you curve around/with the strike so that it glances or is largely absorbed, and doesn't hurt or break as much as it might have.
5. Avoiding the Strike. Slipping punches, jumping back from kicks, ducking grabs, whatever, you just plain get completely out of the way of the strike.
We all use most of these in our play, I would guess. Perhaps the best term is strike-negation, but it sounds a tad clunky to me. It may not fit the denotation, but the connotation of "block" tends to allow for a wider range of admissible techniques, at least among Southern Mainers. Especially to make a point to new students, I will sometimes pointedly refer to an avoidance or muting/rolling as a block. I find it helps. New students often get caught up in blocking EVERYTHING. So, when someone jabs and, as we see all the time, the jab is fully extended a good 18 inches from my head, I'll stand there, motionless and say, "See? There's the block." technically no, it's not a "block" according to Webster or Oxford, but it gets the point across.
Sloppy terminology? Sure, I'm guilty!