Very calm and composed, especially in a stressful situation

बहुत शांत और संयमित, विशेष रूप से तनावपूर्ण स्थिति में

English Usage: Despite the pressure, she remained cool as a cucumber during her presentation.

Hindi Usage: दबाव के बावजूद, अपने प्रस्तुति के दौरान वह एकदम शांत बनी रही।