Well, when I use the word "practice," I really mean the whole enchilada, everything we do to apply the Buddha's teachings in our life. Personally I don't find it useful to apply the term "practice" just to meditation practice, because all the things I do off the cushion -- talking, working, eating, etc. -- influence what occurs on the cushion. So if I don't regard all the off-cushion time as part of "practice," then I'm not being realistic.
I guess I do make a distinction between those times when I have "situational awareness," and those times when I'm more or less obliviously plodding along or even willfully ignorant. The former I regard as "practice," the latter I regard as goofing off. Like now, for example, as I type, I regard this as "practice," because I'm trying to apply the Buddha's teachings in terms of right speech, right effort, etc. But if I'm driving a car in busy traffic and get angry at a slow driver and act on it by honking the horn in a punitive manner (yeah, it happens sometimes, hate to admit), then I don't regard that as "practice." But the moment I become aware that I'm getting angry in slow traffic, for example, the moment I choose to apply the teachings in the moment
, whatever is occuring, I regard that as "practice."
I regard "practice" as any time I am directly engaged in any aspect of the noble 8fold path. I like to think I'm practicing all the time, but I know better. There are times when I'm going in the opposite direction. I don't regard those times as "practice."
I have no specific scriptural support for any of this that I can cite (though Peter's citation is great). I might be completely wrong about how I apply the term "practice." But personally, that's how I use the term, now that you ask. Thanks for asking.