廝殺

to fight at close quarters / hand-to-hand

to fight at close quarters; to fight tooth and nail

mutually / with one another / manservant / boy servant / guy (derog.)

(bound form) together; each other / (bound form) male servant / (bound form) dude; so-and-so (used in 那廝|那厮[na4 si1] and 這廝|这厮[zhe4 si1])

to kill / to murder / to attack / to weaken or reduce / to smart (dialect) / (used after a verb) extremely