If a situation or feeling comes to the boil or comes to a boil, it becomes very strong or active. Their anger came to the boil last week when they officially protested at what they saw as a media campaign against them. The issue has come to a boil because the government has threatened to seize their money. Note: Someone or something can also bring a situation or feeling to the boil. The opposition is sure to bring the dispute back to the boil in any election campaign.