futile
The definition for futile is "Without purpose, completely ineffective." Used in a sentence: Arguing with Andrew is futile because he never changes his mind.
gargantuan
The definition for gargantuan is "Gigantic." Used in a sentence: The gargantuan monster towered over the ten–story bulding.
implausible
The definition for implausible is "Unbelievable." Used in a sentence: Claudia's implausible excuse failed to convince her teacher.
intricate
The definition for intricate is "Having complex and interrelated parts." Used in a sentence: The intricate poem baffled most readers with its numerous obscure metaphors.
iridescent
The definition for iridescent is "Having a lustrous or attractivve quality." Used in a sentence: The movie star's iridescent presence charmed even the hardened reporter.