blue-on-blue

British  

adjective

1. military of or relating to friendly fire

   blue-on-blue contacts

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Etymology

Origin of blue-on-blue

C20: from the colour used to mark a country's own troops and allies on a military map

Example Sentences

There were few "blue-on-blue" clashes during the campaign.

From BBC

Jenrick, who trailed Badenoch for support in the last voting round of MPs, has previously signed up to the yellow card penalty system introduced at the start of the contest and intended to stop "blue-on-blue" infighting.

From BBC

When asked about the blue-on-blue attacks with Tory MPs criticising each other, he said: "We have seen a debate about ideas."

From BBC

"I have deplored the infighting, the sniping, the blue-on-blue, the attacks and the smears," he said.

From BBC

“We can’t tolerate that level of divisiveness in our force. These are blue-on-blue assaults,” he said.

From Washington Post