Esso by Vismut

12 clues contain an extra word to be removed before solving; it’s position in the clue indexes which letter in the answer should have its cell highlighted in the grid. 20 further answers have a letter not indicated by the wordplay; when reading the grid in the usual way these give most of a phrase found in Chambers Dictionary (2016). It all hints at a seven-letter word to be highlighted in the grid.

    1    Rough sea’s direction (4)
    4    Documents about 11 instruments that vary resistance (9)
    10    Box tops beheaded fish (7)
    12    Bird’s first to orchestrate swing trio (6)
    13    Top part of coat ruined (5)
    14    Fastening black bins, they’re both uncovered (6)
    16    Grouse from former prime minister accompanying nurse (8)
    17    Bali dancing nearly all afternoon as organ flue pipe sounds (6)
    20    Bet the Parisienne bowled out first player (7)
    21    Tense insides from journey to base (5)
    23    Star’s been around after bishop died (5)
    24    Remains in outskirts of Armagh (3)
    26    International fish recipe is given boy’s name (5)
    27    Gravel and sand ridge rector rakes ornately (5)
    28    Man on board over the stern to lead crew and Liberian sailors (7)
    33    Wagner’s name ridiculous for what could be a rat (6)
    34    Replace statue or old bench for gathering (8)
    36    Artist securing small piece where the viewer sits (6)
    37    Swimming near poetic cave (5)
    38    Sinister pages? Girl’s short cry for help (6)
    39    Mixed entrée including starter of risotto and, more originally spelt dish (7)
    40    Put extra measure of acidity in pitch for speech writer? (9)
    41    Worry about end of planet (4)

    1    Climbs up ladder and sees rogue getting dressed inside (9)
    2    A dad gets older supplying maintenance provisions (8)
    3    Declined endless deposits in bars possibly (9)
    4    Port tumult (4)
    5    Income support lost by siblings in compounds (6)
    6    Irish learned man found verse in scroll, a villanelle (5)
    7    Columbia uncaged Latin American island animal (5)
    8    Yellow vegetable piece establishes area fruit seller (10)
    9    One getting “must have” cycles (5)
    11    Perennial trouble suffered in retirement (6)
    15    “It’s marmite spread!” – one has no words (10, two words)   
    18    Playful spirits fuse together two elements (9)
    19    Persistent scientists taking the lead and coming up again (9)
    22    Large plant from Prince Edward Island covering entire complex (8, two words)
    25    Frustrate game’s upcoming draw (6)
    29    Trail round district of Venice (6)
    30    Rail alternate parts of reredosse held up (5)
    31    European lawyer’s to hinder established operation (5)   
    32    Lead the Spanish uprising over 24 (5)
    35    Queen retired Mum’s first horse (4)
To enter this competition, send your entry as an image or in list format, indicating the highlightedcells,  to before 8th December 2019. The first correct entry drawn from the hat will receive a book from the Chambers range, which has been donated by Chambers.