drink vs pledge

drink and pledge both are nouns.

Word	Noun	Adjective	Verb	Adverb
drink	Yes	No	Yes	No
pledge	Yes	No	Yes	No

As nouns, pledge is a hyponym of drink; that is, pledge is a word with a more specific, narrower meaning than drink:

As verbs, drink and pledge are synonyms defined as:

Other synonyms of drink include salute, toast, wassail.

drink (noun)	pledge (noun)
the act of drinking alcoholic beverages to excess	a binding commitment to do or give or refrain from something
the act of swallowing	a drink in honor of or to the health of a person or event
any liquid suitable for drinking	someone accepted for membership but not yet fully admitted to the group
a single serving of a beverage	a deposit of personal property as security for a debt
any large deep body of water

drink (verb)	pledge (verb)
be fascinated or spell-bound by; pay close attention to	promise solemnly and formally
take in liquids	bind or secure by a pledge
consume alcohol	give as a guarantee
drink excessive amounts of alcohol; be an alcoholic	propose a toast to
propose a toast to	pay (an amount of money) as a contribution to a charity or service, especially at regular intervals