mark out

1. To draw, establish, or otherwise indicate the boundary of some region or area. A noun or pronoun can be used between "mark" and "out." We went through with the architect and marked out exactly where our property ended and the neighbors' property began. Please mark out the area you intend to excavate.

2. To indicate something visually (on something else). Let me take a pen and mark the route out on this map for you. The surgeon marked out where the incisions needed to be made with a thick black marker.

3. To cross out, obscure, or destroy something with a mark of some kind. The bouncer marked out the name of each guest as they arrived. Someone took a black felt pen and marked the barcodes out of every book in the library.

4. To indicate, identify, or distinguish someone or something as particular type of person or thing. Usually followed by "as." The way I dressed and the music I listened to had always marked me out as a weirdo and an outcast as a kid. The amount of money the film has made marks it as one of the most financially successful in history.

mark out

To establish explicitly the outline, boundary, or shape of some region or thing, by or as if by drawing lines or points around it: We marked out the territory we wanted to explore on the map. Let's mark out the boundaries of the new garden.