Today's word is:
A retreat for times of ill humour - a place to be alone and think. Similar (without the religious context!) to the Latin-derived sanctum sanctorum, with the added connotation that the individual in question is going to the place to be alone while upset.
English; cf. Dutch grollen, 'to grumble'
Loki, the new Mistress of Nerdfury Manor, was quite upset with me when I came home quite late one night after work. She was quite hungry after a long day of laying about and watching traffic through the window! To show her ill humour, she had retreated to her growlery under the bed for a sulk.
All appeared to be forgiven, however, when she heard the familiar sound of a fresh tin of food being opened. At least forgiven, for now.