incursion
a sudden invasion or attack into enemy territory, or an unwanted intrusion into a domain
The military incursion across the border prompted immediate diplomatic protests.
More GRE words starting with I
a person who attacks cherished beliefs or established institutions
attacking or undermining traditional beliefs and institutions
a peculiar habit or feature distinctive to an individual
excessively or blindly devoted to something or someone
extreme admiration or worship of someone or something, often to an excessive degree
to admire or revere someone to an excessive degree
charmingly peaceful and free of trouble
lacking nobility of character; dishonorable
Learn words the way the GRE tests them.
Vocabulary sticks when you meet it in real sentences. Practise these words inside text completion and sentence equivalence questions.