I didn’t want to participate in an evaluation of my coworkers, but I didn’t have a choice.
Somehow the kanji portable turns into the verb to engage in or to participate or to take part in. I suppose if you are portable, you're able to engage in all kinds of things, since you can move all over the place, participating everywhere you can (rather than being not portable and being stuck in one place).
A Taz saw (たずさ) is a saw owned by a Tazmanian, and it is particularly portable. It allows you to participate in all kinds of things, like cutting down trees, or being in a horror film.