[snoh-in-suhm-er] 
| a mat-forming garden plant, Cerastium tomentosum, of the pink family, native to Italy, having white flowers and numerous narrow, white, woolly leaves in large patches, growing in sand. |
| snow-in-sum·mer (snō'ĭn-sŭm'ər) n. A woolly, white, mat-forming perennial herb (Cerastium tomentosum) native to Italy and widely cultivated in rock gardens for its showy white flowers with notched petals. |