These words are comparable in their denotation of reducing the length, extent or duration of something. Shorten means to make or seem to make short or shorter, and can refer either to dimension or duration: angry with the demands of fashion that made it necessary for her to shorten so many pieces of her wardrobe; forced to shorten his lunch hour because of a heavy work schedule; trying to shorten the waiting time at the dentist’s by reading a magazine.

Curtail , cut and lop imply shortening through removal of a part of the whole. Curtail suggests a lessening, as in quality or effectiveness, because of the removal of some important part: a department store whose business suffered when it curtailed its services to suburban customers. Cutting , which suggests an editing process, may or may not remove something important: Some movies seen on TV suffer when they are cut badly to fit into a shortened time slot. Cut may be used very generally for any shortening or reducing process: a cut in expenditure. Lop , in its literal sense, refers to the shortening or cutting off of something which juts out, especially of tree limbs: They lopped the branches that poked over the fence. It has also a colloquial figurative use similar to cut ; The athlet lopped two seconds off the existing record.

Abridge and abbreviate both carry the idea of shortening so that what remains adequately represents the whole. To abridge suggests the cutting away of non-essentials while retaining the core. To abbreviate , generally used in reference to words or phrases, implies shortening by the compression or omission of parts, the remainder standing for the whole: to abridge a novel for its inclusion in a magazine; the abbreviated name of an advertising agency.