[mass noun]a sensation of whirling and loss of balance, associated particularly with looking down from a great height, or caused by disease affecting the inner ear or the vestibular nerve; giddiness (尤指从高处往下看,或因内耳或前庭神经疾病所致的)眩晕
语源
late Middle English: from Latin, whirling', from vertere 'to turn'