plural of ti
"The judge decided to grant him a reduced term under tis, noting his first-time offense and steady employment record."
Initialism of truth in sentencing.
In plain English: Tis is not actually used as a noun; it's just an old-fashioned way of saying "it is."
"The snow has melted from the ground, leaving nothing but bare earth and tis beneath our feet."
Alternative form of 'tis
"The archaic contraction it is, often spelled as tis or its variant forms, frequently appears in older literary texts to convey a sense of timelessness."