Which is the correct usage in English please : "He had philonthropist leanings" or "He had philonthropic leanings" ?
You have to replace only one letter: namely “o” by “a”. The proper English word is philanthropic.
philanthropic = of or concerned with charity: altruistic, benevolent, charitable, eleemosynary, philanthropical
Her volunteer work over the years included serving on the board of directors of Common Sense, a program to encourage philanthropic leanings in children; serving on the advisory committee of an exchange program for French and American students; assisting with fund raising for the Union Settlement Association, an East Harlem social-service organization, and founding a program called Art Tours for Children. She also was a docent at the Metropolitan Museum of Art.