Skookum is a Chinook Jargon word that has historical use in the Pacific Northwest. It has a range of meanings, commonly associated with an English translation of "strong" or "monstrous." The word can mean "strong," "greatest," "powerful," "ultimate," or "brave." Something can be skookum, meaning "strong" or "monstrously significant." When used in reference to another person, e.g. "he's skookum," it conveys connotations of reliability or a monstrous nature, as well as strength, size or hard-working.
Skookum house means jail or prison, cf. the English euphemism "the big house," but here meaning "strong house." Skookum tumtum, lit. "strong heart," is generally translated as "brave" or possibly "good-hearted." In the Chinook language, skookum is a verb auxiliary, used similar to "can" or "to be able." Another compound, though fallen out of use in modern British Columbia English, is skookum lacasset or strongbox.
A related word means turbulent water or rapids in a stream or river, i.e. "strong water" ("chuck" is Chinook Jargon for "water" or "stream" or "lake"). There are three place names in British Columbia, one in Washington, and one in Idaho using this word. Also skookum lake in oregon. Of the British Columbia skookumchucks, one is a famous saltwater tidal flow narrows at the mouth of Sechelt Inlet, the others at rapids on the Lillooet and Columbia Rivers, and also Skookumchuck Rapids Provincial Park on the Shuswap River, just downstream from Mabel Lake in the Monashees region. The Skookumchuck River in Washington is a robust tributary of the Chehalis River. Idaho's Skookumchuck Creek meets the Salmon River south of Whitebird, Idaho just after being crossed by U.S. Highway 95. While the tidal flow rapids at the mouth of Sechelt Inlet is the Skookumchuck on the British Columbia coast, the term is used in a general sense for other patches of rough water, typically tidal-exchange rapids at the mouths of other inlets or bays, which are a regular feature of the Inside Passage.