adjetivo

difícil: difficult, hard, tough, tricky, arduous, trying

duro: hard, tough, stiff, rough, crusty, severe

rígido: hard, rigid, stiff, stringent, inflexible, stern

árduo: hard, arduous, difficult, tough, painful, trying

forte: strong, hard, heavy, sharp, high, robust

firme: firm, steady, strong, tight, steadfast, hard

severo: severe, stern, harsh, grim, strict, hard

rijo: hard, stiff, tough, wiry, strong, stalwart

sólido: solid, sound, strong, firm, hard, massive

áspero: rough, harsh, rugged, ragged, coarse, hard

apertado: tight, pressed, narrow, squeezed, hard, closed

vigoroso: vigorous, strong, robust, strenuous, lusty, hard

insensível: insensitive, insensible, callous, unfeeling, unresponsive, hard

calcário: limestone, calcareous, chalky, hard, limy

advérbio

duramente: hard, hardly

asperamente: roughly, rough, hard, hardly, hardily

perto: near, by, about, aboard, hard, anigh