Green’s Dictionary of Slang

mulvather v.

(Irish) to confuse.

1825		Pierce Egan’s Life in London 9 Oct. 291/2: Oh, your Worship, don't mind what they say, and just see how Roger will molvathur them.
1851		‘The Fine Ould Irish Gintleman’ in Irish Songster 26: His senses were completely mulvathered.
1891		B. Stoker Snake’s Pass 19: He was so much mulvathered at the Shnake presumin’ to sthay, [...] that for a while he didn’t think it quare that he could shpake at all.

In derivatives

mulvathered (adj.)

(Irish) drunk.

1832

S. Lover Legends and Stories 188: I knew the villain was mulvathered.