When looking for synonyms for the word "contentless," which refers to something that lacks substance or meaning, one might consider words like empty, hollow, meaningless, superficial, or vapid. Other options include barren, insipid, pointless, valueless, or vacuous. Additionally, someone seeking to express disappointment in the emptiness of something might use words like disappointing, dissatisfying, unfulfilling, or unsatisfactory. Ultimately, the choice of synonym will depend on the specific context and the writer or speaker's intent and tone. However, with a plethora of options to choose from, there is no shortage of vocabulary to convey the idea of something being contentless.