ETYM Old Eng. egre sharp, sour, eager, Old Fren. agre, aigre, French aigre, from Latin acer sharp, sour, spirited, zealous.
Having or showing keen interest or intense desire or impatient expectancy.

ETYM Old Eng. impacient, French impatient, from Latin impatiens; pref. im- not + patiens patient. Related to Patient.
1. Restless or short of temper under delay or opposition.
2. (Usually followed by 'to') Full of eagerness; SYN. raring.