Wordwizard

The first OED citation is 1657. The 'origin' is no more than a blend of the two words 'self' and 'esteem'.

knowledge comes from the northern English dialect word knaulage or knowleche and is first cited sometime before 1300. The first element is identical with the SE word know; the problem lies in the second part, the 'ledge'. The OED offers a lengthy and complex note, the burden of which is that the ver...

The image is of tail, which should be wagged by a dog, taking control of the animal.

Your friend is, I have to say, talking nonsense. Where do they get these ideas? The word comes from Latin 'rumen', the throast, the gullet, and was originally applied to cows chewing the cud.

'smack', used advervbially, with, or as with, a smack; suddenly and violently; slap plus 'dab', adv. With a dab, or sudden contact.

craw comes from a Teutonic root and is cognate with such words as Dutch 'kraag', the neck.

Pound is something of a problem. It is not found till near the end of the Middle English period, i.e. c. 1450. A possible root, Anglo-Saxon 'pund', is known only in comb. 'pund-fold' and an early ME. 'pundbreche' or 'pound-breach' (found in the laws of Henry I). It is supported by the derivatives '(...

The antibiotic agent obtained from cultures of the mould Penicillium notatum ( a genus of ascetomycetous fungi, including several of the common moulds); hence, any of a group of antibiotics that are all derivatives of 6-amino-penicillanic acid in which a radical replaces one of the amino hydrogen at...

No, a palindrome, from Greek 'palindromos', running backwards.

Both forms are noted in the Dict. of American Regional English, which defines 'oma' as grandmother, with the label 'esp. in German settlement areas'; 'opi' and 'opa' are grandfather, and similarly labelled. The latter seems to be an elision of 'grosspapa' (? or 'grosspapi'); presumably oma is 'gross...

Latin 'spiritus', breath, breathing. The earlier English uses of the word are mainly derived from passages in the Vulgate, in which spiritus is employed to render Gr. 'pneuma' and Heb. 'ruah'. The translation of these words by 'spirit' (or one of its variant forms) is common to all versions of the B...

The words blends fire and plug, a tap or stopcock.

The 'liar' version is a weak use of the technical pathological, meaming grossly abnormal in properties or behaviour

I can find no origin, merely an attribution to US slang, and a first citation of 1868.

The term is first cited in 1889 and seems to have been a US coinage.

How long is a piece of string ... there are thousands, maybe tens of thousands, given the etymology of so much English. What I suggest, however, is that you get a copy of the Oxford Dictionary of Foreign Words and Phrases (OUP 19970. This boasts '8000 entries' from '40 languages'. Good luck.