Definitions of trimmer:

• noun:   joist that receives the end of a header in floor or roof framing in order to leave an opening for a staircase or chimney etc.
• noun:   capacitor having variable capacitance; used for making fine adjustments
• noun:   a machine that trims timber
• noun:   a worker who thins out and trims trees and shrubs
• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #14731)