Without defining or differentiating the technical terms and formulas and disregarding any reference to fishing boats, there are several terms commonly used in regards to the yachting market.
IMHO, in general a trawler is a subcategory of Powerboat or Motoryacht and refers to a full displacement hull which usually has a maximum speed around 9 knots and carries sufficient fuel for long passages. There are semi-displacement hulls that have speeds in the range of 12-16 knots that I (with reluctance in using the oxymoron) call "Fast Trawlers" and while they don't have transoceanic range, they usually have engines and fuel capacity to go some reasonable distance without re-fuel.
While single or twin engines, hard chines, round bottoms, bilge keels, stabilizing sail, or flopper-stoppers, can differentiate manufacturers or their models, practical trawler attributes such as Portuguese bridge, forward sloping windows, and high freeboard frequently give boats the appearance that endears them to the trawler nomenclature.
Trawlers that go overboard (NPI) on amenities and grandiosity sometime deserve the label of Trawleryacht. Those that promote exceptional range or are capable of self-sufficiency in remote locales, use the newish term Expedition Yacht.