wwh: Jes' 'cuz I'm procratinating, here's a broad speculation with n'er a twit of truth in it...

To lure is to attrack and trap.

So, the allure was that walkway up high where some whistler would whistle a happy tune. The enemy would sneak up to take a shot at the decoy on the wall, and kaboom! Down would fall the machicolations and machinations and whatever those Machiavellian missiles and hot metals you and tsuwm were writing about.

Sometimes they'd even let a damsel strut on the allure with a cone on her head from which a wispy veil would wrestle seductively with the wind. The sneaky rascals, intoxicated with her seeming beauty, would creep up and kaboom!!! Down would fall again the molten metals and even some offal from the garderobe.

Over time, the defense-turned-offense purpose of the allure got all mixed up with that damsel, and the verb was born.

To allure became, not only to pull into machicolations, but also to pull on the heart strings.

All's fair in love and war, and sometimes the two become one.

WW