/tmp/Chicken/lib$ cat amodule.scm
(module amodule (afunc)
 (import chicken scheme)
 (define (afunc x) 
  (* x x)))
/tmp/Chicken/lib$ 

/tmp/Chicken/lib$ csi

CHICKEN
(c) 2008-2016, The CHICKEN Team
(c) 2000-2007, Felix L. Winkelmann
Version 4.11.0 (rev ce980c4)
linux-unix-gnu-x86-64 [ 64bit manyargs dload ptables ]
compiled 2016-05-28 on yves.more-magic.net (Linux)

#;1> (include "your-path/amodule.scm")
#;2> (import amodule)
#;3>  (afunc 2)
4
#;4>