thunderbird

Short definition from Wiktionary

Noun

1. 1
   A mythological bird, often associated with stormy weather, especially in various indigenous North American mythologies.
2. 2
   The golden whistler, an Australian insectivorous songbird (Pachycephala pectoralis, formerly Pachycephala gutturalis), whose male is conspicuously marked with black and yellow, and has a black crescent on the breast.
3. 3
   Alternative letter-case form of thunderbird.
4. 4
   A locomotive stored at a strategic point on the network so as to be available to quickly rescue a failed train.

Proper noun

1. 1
   Mozilla Thunderbird.
2. 2
   Ford Thunderbird.