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"
a representation of a person (especially in the form of sculpture); "the coin bears an effigy of Lincoln"; "the emperor's tomb had his image carved in stone"
the activity of contributing to the fulfillment of a need or furtherance of an effort or purpose; "he gave me an assist with the housework"; "could not walk without assistance"; "rescue party went to their aid"; "offered his help in unloading"
a resource; "visual aids in teaching"; "economic assistance to depressed areas"
a gift of money to support a worthy person or cause