strong A1

/stɹæŋ/ Having a lot of physical power.

enstrengthen C2+

/ɛnˈstrɛŋθən/ to make strong or stronger (archaic or rare)

strengthful C2+

/ˈstrɛŋθfəl/ full of strength; powerful (archaic)

strengthless C2+

/ˈstrɛŋθləs/ lacking strength; feeble or powerless