pledge

What it means

1. To make a solemn promise (to do something).

   pledge allegiance to the flag

   1 more example

   In those battles there was the proud waving of eagle-feathered war bonnets and the strong courage of warriors who dared to carry a sacred buffalo shield, although a man who carried one was pledged not to retreat.

   1950, Dorothy M. Johnson, Scars of Honor; in Indian Country, London: Corgi, 1961, page 142

   Synonyms: undertake

2. To deposit something as a security; to pawn.
3. transitiveTo give assurance of friendship by the act of drinking; to drink to one's health.

   Reach me my golden cup that stands by thee, And pledge me in it first for courtesy.

   1852, Matthew Arnold, Tristram and Iseult

   1 more example

   HARDCASTLE [Taking the cup.] I hope you'll find it to your mind. I have prepared it with my own hands, and I believe you'll own the ingredients are tolerable. Will you be so good as to pledge me, sir? Here, Mr. Marlow, here is to our better acquaintance. [Drinks.]

   1773, Oliver Goldsmith, She Stoops to Conquer

In a sentence

pledge allegiance to the flag

Where it comes from

1. Frankish*plehan“to pledge; to support; to guarantee”
2. Medieval Latinplevium
3. Old Frenchplege
4. Anglo-Normanplege
5. Middle Englishplege
6. Englishpledge

From Middle English plege, from Anglo-Norman plege, from Old French plege (Modern French pleige) from Medieval Latin plevium, plebium, from plebiō (“to pledge”), from Frankish *plehan (“to pledge; to support; to guarantee”). Akin to Old High German pflegan (“to take care of, be accustomed to”), Old Saxon plegan (“to vouch for”), Old English plēon (“to risk, endanger”). More at plight.