Across:
1 Weird (ODDITY) old (O-) deputy head (‘deputy’ head = -D-) from college (Dublin Institute of Technology = -DIT-) with ponytail (‘pony’ tail = -Y) (ODDITY),
4 Horrified (DISMAYED) local kicked the bucket (died = DI-ED) containing dug up (= reversal indicator) tubers (yams = -SMAY-) (DISMAYED),
9 Caddie to finish (‘caddie’ to finish = E-) reading (from the 3Rs = -R-) tirade (-RANT) (ERRANT) wandering off course (ERRANT),
10 Cornea is (cornea is = SCENARIO) damaged? (= anagram indicator) One of those in the theatre outlined this possibility! (SCENARIO),
12 Wrote a tasting note (DESCRIBED) for bubby (= anagram indicator) ciders (ciders = DESCRI-) perfect for lying down (-BED) (DESCRIBED),
13 Wildlife park (zoo = -OOZ-) set up (= reversal indicator) in Belgium (B-E) (BOOZE) – is it something the Trappist monks would put their name to locally? (Trappist monks make beer/ BOOZE in Belgium),
14 Detailed (g) transport (‘bring’ without ‘g’ = brin = BR-IN-) carrying additional stuff (-OTHER- stuff) from the bar (-LAW) (BROTHER-IN-LAW) for sister’s partner (BROTHER-IN-LAW),
18 Someone’s confidence (NERVE -) using GPS (tracking) heading off (t) (‘tracking’ without ‘t’ = - RACKING) (NERVE-RACKING) can be stressful (NERVE-RACKING),
21 These left all the same (‘these’ left ‘all the same’ = allam = LLAMA) with wool producer (LLAMA),
22 Relative (AUNT) behind (= position indicator) torture (AGONY) (AGONY AUNT) of trouble-shooting columnist (AGONY AUNT),
24 To absent friends (CHIN-CHIN) from Church (CH-) in (-IN-) Switzerland (-CH-) and up (= reversal indicator) north (NI = -IN) (CHIN-CHIN),
25 Saucy type (TAHINI) upsets (= reversal indicator) bowler (hat = TAH-) in (-IN-) taking second wicket (second ‘wicket’ = -I) (TAHINI),
26 Providing intelligent directions (EDIFYING) to engineer (E-) on last legs (dying = -D-YING) going around island (-I-) and starting to flag? (starting to ‘flag’ = -F-) (EDIFYING),
27 Attention seeking publicity (STUNTS) for hampers (hampers/hinders = STUNTS).
Down:
1 What a borrower might do (OWE A DEBT) for Jones’ partner (Dow Jones) heading off (D) (‘Dow’ without ‘d’ = OW-) to prepare (= anagram indicator) debate (debate = E A DEBT) (OWE A DEBT),
2 Ridicule (DERISION) of Ironside (ironside = DERISION) adaptation (= anagram indicator),
3 Baritones disregard bias (‘baritones’ disregard ‘bias’ = rtone = TENOR) of male singer (TENOR),
5 Episode (INCIDENT) from The Office (ROOM) (INCIDENT ROOM) – the one where the police are wondering whodunnit (INCIDENT ROOM),
6 Sick (= anagram indicator) conman (conman = MON- -ANC) admits bacterial disease (-T B-) on top of lumbago (on top of ‘lumbago’ = -L-) (MONT BLANC) is a mountain to climb (MONT BLANC),
7 Daisy’s relative (YARROW) at journey’s end (end of ‘journey’ = Y-) taking Dart (dart -ARROW) (YARROW),
8 Snored (snored = DRONES) badly (= anagram indicator) in low humming sounds (DRONES),
11 A small word (ABBREVIATION) from USA, for example, literally speaking (USA = ABBREVIATION),
15 Church leaders (HIERARCHY) greet (HI-) rare (rare = -ERAR-) review (= reversal indicator) that’s a fair bit (half of) touchy (half of ‘touchy’ = -CHY) (HIERARCHY),
16 Guillotined, missing leg (‘guillotined’ missing ‘leg’ = uilotind = DILUTION) and weakening (DILUTION),
17 Priest (Priest = E- TRIPS) at fault (= anagram indicator) over green light (-GO) (EGO TRIPS) for self-indulgent outings? (EGO TRIPS),
19 Sounds like (= homophone indicator) lake (‘lough’ = ‘loch’ = -LOCH-) in Clare (C-E) (CLOCHE) offers protection to those in the plot (CLOCHE),
20 Pussy foot (paw = WAP-) around (= reversal indicator) centre (it) with (centre ‘with’ = -IT-) one (-I) (WAPITI) buck (WAPITI deer /stag),
23 Pick off tipsy cake (‘pick’ off ‘tipsy cake’ = tsyae = YEAST) one of the ingredients for making bread (YEAST).