"A spider or a mouse?"
Translation:עכביש או עכבר?
Introducing all these words with zero indication of how they are pronounced is very unhelpful. I think the first time a word appears it should always be accompanied with a recording.
The default is the masculine form, you'd use the feminine form only if you know somehow that the spider is indeed a female spider.
Do the words for spider and mouse share a common stem ע-כ-ב? If so - what's its primary meaning?
I suppose, "עכבר" has a 4-letter root. Rarely, but it happens. Because "ר" doesn't look like a morpheme.
According to Strong's:
mouse = עכב (Chaldee devoring) + בר (in the signification of corn).
spider = probably from an unused root in the literal sense of entangling; a spider (as weaving a network