i Prize Cryptic Crossword No 506

[souxie]

23 Across, Greek area,one within island (5) ????A IONIA ?
15 Down, Get rid of upturn in risk that is restricting guy(9)E?A???A?E
ERADICATE ?
19 Down, Source of howling prevents a good deal of attention (7) B???H?E
25 Down, Walked out,though not following unacceptable service (3) L?T

Many Thanks in Advance

[bibblebub]

23a) yes - one = I inside island = IONA
15d) yes - upturn in risk = ERAD, that is = I.E., guy = CAT

[Fibonacci]

19 banshee

[bibblebub]

19d) BANSHEE - prevents = BANS, a good deal of attention = HEE(d)

25d) LET - walked out though not following = LE(f)T

[mallyh]

25d let (tennis)

[souxie]

Many thanks to all.