Hard

costar

(requiring a lot of effort to do or understand)

difícil

(requiring a lot of effort to do or understand)

difícil

(severe)

duro

(resistant to pressure)

duro

(requiring a lot of effort to do or understand)

duro

(severe)

duro

(of water, high in dissolved calcium compounds)

fuerte

(of drink: strong)

incuestionable

(unquestionable)

palote

(sexually aroused; having an erect penis)

palote

(sexually aroused; having an erect penis)

tranca

(requiring a lot of effort to do or understand)