elusive
adjective /ɪˈluːsɪv/
  /ɪˈluːsɪv/
 - difficult to find, define or achieve
- Eric, as elusive as ever, was nowhere to be found.
 - the elusive concept of ‘literature’
 - A solution to the problem of toxic waste is proving elusive.
 
Extra ExamplesTopics Difficulty and failurec1- Further movie roles have proved somewhat elusive for the young actor.
 - He was searching for the ever elusive ‘perfect job’.
 - Sleep was strangely elusive.
 - The murderer remained frustratingly elusive.
 - Truth is a notoriously elusive quality.
 
Oxford Collocations Dictionaryverbs- be
 - prove
 - become
 - …
 
- extremely
 - fairly
 - very
 - …
 
Word Originearly 18th cent.: from Latin elus- ‘eluded’ (from the verb eludere) + -ive.