TID or tid may refer to:
* Nitrogen–phosphorus detector, Thermionic detector, a detector used in gas chromatography based on the principle of ionization and measuring a change in electron flux
* Absorbed dose, Total ionizing dose (related to ionizing radiation)
* Transient ischemic dilation, a finding on a nuclear cardiology test consistent with coronary artery disease
* TID class tug, a British tugboat design of World War II
* TID (musician)a musician from Tanzania
* Traffic identifieran identifier used for traffic flows in 802.11 wireless local-area networks
*''ter in die'', Latin for three times daily; usually refers to prescription medication dosage (e.g. TID)
* Tag identification memory, in a Gen 2 RFID tag, this consists of memory about the tag itself, such as the tag ID
* Transportation improvement district
* Travelling Ionospheric Disturbancea type of Ionosphere#Ionospheric perturbations, Ionospheric perturbation
* Truncated dodecahedron
* Travel itinerary directory
* ''Tobacco Induced Diseases''a peer reviewed journal
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