plumbs / plums are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
plumbs: (verb) measure the depth of something. (verb) weight with lead. (verb) examine thoroughly and in great depth. (verb) adjust with a plumb line so as to make vertical.
plums: (noun) any of several trees producing edible oval fruit having a smooth skin and a single hard stone. (noun) any of numerous varieties of small to medium-sized round or oval fruit having a smooth skin and a single pit. (noun) a highly desirable position or assignment.
plumbs: NA
plums: p·l·AH·m·z
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)