Sentence:  "But there weren't many crabs in those days," the old man wandered on. "They were fished out, and they were great delicacies. The <WSD>open season</WSD> was only a month long, too." 
Meaning of the word marked with <WSD> tags:  or (for) to designate the kind of animal hunted A period of time during the calendar year when authorities within a jurisdiction permit the unrestricted hunting of one or more kinds of animal wildlife.