air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
breathing device consisting of a bent tube fitting into a swimmer's mouth and extending above the surface; allows swimmer to breathe while face down in the water
struggle in opposition; "She tugged and wrestled with her conflicts"
pull hard; "The prisoner tugged at the chains"; "This movie tugs at the heart strings"
pull or strain hard at; "Each oar was tugged by several men"
move by pulling hard; "The horse finally tugged the cart out of the mud"
tow (a vessel) with a tug; "The tugboat tugged the freighter into the harbor"
strive and make an effort to reach a goal; "She tugged for years to make a decent living"; "We have to push a little to make the deadline!"; "She is driving away at her doctoral thesis"