ガン, まる, まる.める, まる.い, ま, わ, わに
round, full (month), perfection, -ship, pills, make round, roll up, curl up, seduce, explain away
JLPT2 G2 S3 F542
The relevant seal inscription form is 人 person bending beneath a curved line# suggesting a cliff (compare 宛) → *round*; *circular*; *spherical* (← posture of the figure) → *roll up*; *make a ball of*; *wad up*. Also, *entire* (← complete ← round). *Suffix in the names of ships* is by confusion with the classical Japanese term まろ (maro), meaning "lineage".
[Full Kanji Etymology List]