tighten — to make something tighter or more secure

a bicycle mechanic grips a wrench firmly and turns it clockwise on a loose wheel bolt. His muscles tense as he applies steady pressure to secure the connection properly. The bolt gradually moves deeper into position as the wheel becomes more stable. What was once a wobbly, dangerous wheel now sits firmly attached to the bicycle frame. The mechanic's apprentice watches nearby while organizing tools on the workbench. Other customers wait with their bikes in the background of the busy shop. making something tighter and more secure through careful adjustment