损失 works as both noun and verb. As noun: 造成损失 (cause losses), 经济损失 (economic loss). As verb: 损失了很多 (lost a lot). 损失惨重 is a four-character set phrase meaning 'suffer heavy losses.'
usage
损失 (loss — financial/material) vs 丧失 (sàngshī, to lose — abstract things like confidence, ability) vs 失去 (shīqù, to lose — people, opportunities).