spitting image（n.）
"exact likeness," by 1880, probably based on earlier phrases such as spit and image (1847). Uncertainty of the early forms (also spitten image, 1875; spit en image 1880, etc.) suggests it is from spit (n.1) in the "exact likeness" sense (attested by 1805) + image (n.) but conformed to present-participle forms.
That use of spit (n.) seems to be based on a once-common expression, to say one was as like another as if he had been spit out of his mouth, which is attested from at least 1580s in English, perhaps from a similar expression in French.
该词起源时间：1880年