Weakling

сла́бый

slábyj

(weak, either physically, morally or mentally)

хи́лый

xílyj

(weak, either physically, morally or mentally)

слаба́к

slabák

(person of weak or even sickly physical constitution)

слаба́к

slabák

(person of weak character)

тря́пка

trjápka

(person of weak character)

хлю́пик

xljúpik

(person of weak character)