malt (n.) Look up malt at Dictionary.com
Old English malt (Anglian), mealt (West Saxon), from Proto-Germanic *maltam (cognates: Old Norse malt, Old Saxon malt, Middle Dutch, Dutch mout, Old High German malz, German Malz "malt"), from PIE *meld- (see melt (v.)), extended form of root *mel- "soft," probably via notion of "softening" the grain by steeping it in water before brewing. Finnish mallas, Old Church Slavonic mlato are considered to be borrowed from Germanic.
malt (v.) Look up malt at Dictionary.com
mid-15c., "to convert grain to malt," from malt (n.). Meaning + "to make with malt" is from c.1600. Related: Malted; malting. Malt liquor (which is fermented, not brewed) first attested 1690s. Malted "a drink with malted milk" is from 1945.