Oxford Learner's Dictionaries presents 'WhatsApp' as a verb and noun.
WhatsApp™ verb
/ˈwɒtsæp/, /ˌwɒtsˈæp/
/ˈwʌtsæp/, /ˌwʌtsˈæp/
[transitive, intransitive]
WhatsApp (somebody) to send a message, photo or video using the
WhatsApp service.I WhatsApped Abigail yesterday to let her know what had happened.
She spent most of the evening WhatsApping and taking selfies.
Is it acceptable to use 'WhatsApp' in formal contexts as a verb?
Best Answer
I don’t like it (merely my prejudice) but I suggest it is acceptable in the same way that other nouns relating to communication became verbs.
Telephone and phone were nouns for the device; they are now also verbs. “I will phone on Friday”
Text was a noun for a set of words; it is now also a verb. “Please text me the election result”
Google was a name for a company; it is now also a verb. “Please google Anthimeria”