[shing-guh
l] 
noun, verb, -gled, -gling.| 1. | a thin piece of wood, slate, metal, asbestos, or the like, usually oblong, laid in overlapping rows to cover the roofs and walls of buildings. |
| 2. | a woman's close-cropped haircut. |
| 3. | Informal. a small signboard, esp. as hung before a doctor's or lawyer's office. |
| 4. | to cover with shingles, as a roof. |
| 5. | to cut (hair) close to the head. |
| 6. | hang out one's shingle, Informal. to establish a professional practice, esp. in law or medicine; open an office. |
| 7. | have or be a shingle short, Australian Slang. to be mentally disturbed, mad, or eccentric. |
hang out one's shingle
Open an office, especially a professional practice, as in Bill's renting that office and hanging out his shingle next month. This American colloquialism dates from the first half of the 1800s, when at first lawyers, and later also doctors and business concerns, used shingles for signboards.