perfunctory
per-FUNK-tuh-reeadjMeaning done only as a routine, with little care or interest
Memory hook per-FUNK-tory: no FUN, just get THROUGH it. Rosa plays “Happy Birthday” with a blank face, no fun and no feeling, only to get through it. Her playing is perfunctory.
Jonah gave his aunt a perfunctory wave without looking up from his book.
In context Her thank-you note was perfunctory: just “Thanks for the gift,” with no word about what the gift was or whether she liked it.
Similar halfhearted, routine, mechanical, superficial
Opposite wholehearted, thorough, careful
From Late Latin perfunctorius, from perfungi, “to get through with”: per (through) + fungi (to perform).