Definition of gasp noun from the Oxford Advanced American Dictionary

gasp

noun
/ɡæsp/
 
 
a quick deep breath, usually caused by a strong emotionto give a gasp of horror/surprise/reliefHis breath came in short gasps.IDIOM

your/the last gasp

the point at which you/something can no longer continue living, fighting, existing, etc.
see also last-gaspyour last gaspthe last gasp