knows the ins outs (verb) know the ropes: understand the particulars of a situation
Sinonime: anorexic, atrophied, attenuated, bony, cadaverous,
drawn,
emaciated, famished, gaunt, haggard, lank, lean, scrawny, shrivelled, shrunken, skin and bones, skin-and-bones, skinny, starved, thin, underfed, undernourished, withered