A geomancer is an expert in geomancy: an old way of claiming to read hidden meaning from the earth. Here is the messy part, and it matters in Taiwan. In old European and Arabic use, geomancy was a fortune-telling system. You make dots or marks, or you look at patterns in soil or sand, and you read a figure from that. The person who does it is a geomancer. That is the word's home meaning in learner dictionaries. But when English writers talk about Chinese and Taiwanese life, they often use geomancer for a 風水師 — someone who reads a site (a house, a grave, a shop) and says how land, water, and direction will affect luck. That is not the same craft as the old European sand-and-dot system, though both claim to read the earth. In a Taiwan story about a family choosing a grave or a shop, the English word almost certainly means the 風水 person. In a book about medieval magic, it means the European or Arabic art.

風水師、風水先生（歐洲舊義則是地占／土占的術士；台灣故事裡多半是風水）