1) A structure attached to a larger building, often with a sloping roof, a lean-to.
1450 In Clx thakbord’ emptis ... pro j pentyce ibidem inde faciendo vijs, York
1464-5 ‘making lez pentessez in le Chirchelane’, Hull
1550 I give ... for the making of a pentice or a covering rounde aboute the crosse in the market plaice ... substanciall and stronge with tymber and tyell vjli xiijs iiijd, Newark. Popular etymology was responsible for the modern spelling ‘penthouse’: 1714 an incroachment in the street before the Swan Tavern, 15 yds long and 2 foot in breadth, and a penthouse along the said front, Leeds.