to put something right, change something in order to make it suitable for new conditions or use
become or make prepared, adapted
Cases of word usage
1) a person who cuts out, fits and alters clothes; a workman who fits and adjust parts of an engine, machine etc (fitter)
2) to control (something) using rules; to adjust (an apparatus, mechanism) in order to get the desired result (regulate)
3) a series of notes forming a melody (of a song etc); to adjust (a musical instrument) to the right pitch; to adjust or adapt (the engine of a vehicle) so that it gives its best performance (tune)