please allow saving a collocation, a long phrase instead of just a word or the whole sentence

I find it quite limited that LR only allows either saving the whole sentence or just a word to my dictionary. It doesn’t match most high level English learner need. For example, provided this sentence: In every corner of the city, one might be able to spot a free iced tea dispenser on the street, cool and ready for everyone to quench their thirst on a sweltering Saigon day.
→ people might know what thirst means, but in this sentence i wanna learn the phrase “quench my thirst”. i don’t wanna save the whole sentence cuz it’s too long for review, only the phrase.

please help and add this function :") then it would be the most perfect app out there to saving english words from english resources!!!

looking forward to team’s reply! thanks for considering. have a great day,
user from Vietnam