GRE nebulous Definition Vague or unclear in form or meaning. Example "He had a nebulous idea of what he wanted to do after graduation." Sign in to save GRE PDF — $25 ← nebula necessitate → Related words GRE awe GRE smithereens GRE abacus SAT abase GRE abash GRE abate GRE abbreviate GRE abbreviation SAT abdicate SAT abdomen GRE abduct GRE aberrant