The reason for taking preparatory or precautionary measures. It is something you do just in case a just-in-case situation occurs. It is an answer to a why question to explain something you are doing to prepare for a just-in-case situation.
Q: "Why are you bringing three roles of duct tape?" A: "justincasers"
"Let me have your phone number justincasers."
"Let me have your phone number justincasers."
by mindopener April 04, 2009