His untrustworthy behavior made it difficult for his colleagues to rely on him during the project.
synonyms
deceitfulunreliabledisreputable
word origin — The prefix 'un-' means 'not' combined with 'trustworthy' from 'trust' + 'worthy', meaning deserving of trust.
SAT Vocabulary Level 3 — Set 173
Set 173 of SAT Vocabulary Level 3 covers 5 words: untrustworthy, prosaic, opalescent, unproductive, outlandish. Each entry below includes its definition, an example sentence, and synonyms — practice them with the interactive cards above.
untrustworthy · adjective/ʌnˈtrʌstˌwɜrði/
not deserving of trust or confidence
His untrustworthy behavior made it difficult for his colleagues to rely on him during the project.
Synonyms: deceitful, unreliable, disreputable
Origin: The prefix 'un-' means 'not' combined with 'trustworthy' from 'trust' + 'worthy', meaning deserving of trust.
prosaic · adjective/proʊˈzeɪ.ɪk/
dull or lacking in imagination or creativity
Despite the fascinating subject matter, the film was ultimately let down by its prosaic dialogue.
Synonyms: mundane, unimaginative, commonplace
Origin: The word 'prosaic' comes from the Latin 'prosaicus', which means 'matter-of-fact, straightforward', from the word 'prosa', meaning 'prose'.
opalescent · adjective/oʊ.pəˈlɛs.ənt/
having a play of lustrous colors like those of an opal
The opalescent surface of the water shimmered under the moonlight, revealing hues of blue and green.
Synonyms: iridescent, pearlescent, shimmering
Origin: The word 'opalescent' is derived from 'opal', which comes from the Latin 'opalus' and the Greek 'opallios', meaning 'to see a change in color'.
unproductive · adjective/ʌnprəˈdʌktɪv/
not producing or able to produce significant results
The meeting turned out to be unproductive, leaving everyone frustrated and without a clear plan of action.
Synonyms: ineffective, unfruitful, futile
Origin: The word 'unproductive' comes from the prefix 'un-' meaning 'not' combined with 'productive', which originates from the Latin 'producere', meaning 'to lead forth, bring forth'.
outlandish · adjective/aʊtˈlændɪʃ/
strikingly unconventional or far-fetched
Her outlandish ideas about time travel fascinated everyone at the conference.
Synonyms: bizarre, eccentric, ludicrous
Origin: The word 'outlandish' originates from the Middle English 'utlandish', which combines 'outland' (meaning foreign or strange) and the suffix '-ish', indicating a quality or characteristic.