mar·a·thon·er 
(mărə-thŏn′ər)
(mărə-thŏn′ər)n.
One that participates in a marathon, especially a marathon runner.
mara·thon′ing n.
- circularly
- circular measure
- circular mil
- circular saw
- circulate
- circulating library
- circulation
- circulative
- circulator
- circulatory
- circulatory system
- circum-
- circumambience
- circumambiency
- circumambient
- circumambiently
- circumambulate
- circumambulation
- circumboreal
- circumcise
- circumciser
- circumcision
- circumduction
- circumference
- circumferential