| Answer | Crossword Clue |
|---|---|
| SIGNAL | One if by land, or two if by sea |
| CODE | One if by land, two if by sea, etc. |
| CODES | "One if by land, two if by sea" and others |
| CODE | "One if by land, two if by sea," e.g. |
| CODE | One if by land, two if by sea, e.g. |
| PAULREVERESRIDE | Longfellow poem featuring the line "One if by land, and two if by sea" |
