Tarps, autos, bikes, photos, prams...
Could the term you're looking for be "abbreviation?" ;)

Here in the homeland of Harley-Davidson, the only term above that would need clarification in conversation is "bike", since it is an obvious abbreviation of motorcycle. In this case, the intended meaning can usually be figured out contextually, by looking for the nearly-ubiquitous Harley logo somewhere on the speaker's body. Leather and bandana headgear are also clues. The consequences of mistaking a Harley for a Schwinn are enormous.

P.S. I just ran the above post through the site's Spell Check: it suggested that for Harley-Davidson, I may have meant "harlot."