IPA: //ˈsɛkrɪtər//
KK: /ˈsɛkrɪtər/
A person or thing that secretes, especially a gland or cell that produces and releases substances.
The secreter in the body helps to produce hormones that regulate various functions.
Secreter is derived from the word 'secret' (from Latin 'secretus', meaning set apart or hidden) and the suffix '-er' (meaning a person who). Thus, a secreter is a person who keeps things hidden or confidential.
Think of someone who keeps things 'set apart' ('secretus') — that's why a secreter is a person who keeps secrets.