a measuring instrument that sends out an acoustic pulse in water and measures distances in terms of the time for the echo of the pulse to return; "sonar is an acronym for sound navigation ranging"; "asdic is an acronym for antisubmarine detection investigation committee"
the warmest season of the year; in the northern hemisphere it extends from the summer solstice to the autumnal equinox; "they spent a lazy summer at the shore"
a section of something that is long and narrow; "a length of timber"; "a length of tubing"
the linear extent in space from one end to the other; the longest horizontal dimension of something that is fixed in place; "the length of the table was 5 feet"
the property of being the extent of something from beginning to end; "the editor limited the length of my article to 500 words"