Nicknames for forenames:
Bartly, Bartel, Bat - Bartholomew
Bridget - Delia, Brid, Bedelia, Brigitta, Bridie, Brita, Brydie, Brighid
Cassie - Catherine
Catherine - Caitlin, Cathleen, Catriona, Karen, Karina, Kathleen, Kathryn, Cathy, Kate, Kathy, Katie, Kay, Kit, Kitty, Katharos
Charles - Cormac, Carolus
Con, Neilly - Cornelius
Criddy - Christian
Elizabeth - Sheila
Eoghan - Owen
Hanora - Johanna
Helen - Eileen, Elaine, Eleanor, Ellen, Helena, Helene, Nell, Nellie, Nelly
Honor, Honoria, Norah, Noey, Onny - Hanorah
James - Jacob, Jacobus, Seamus
Jeremiah - Dermot, Demetrius, Diarmuid, Darby
Joan - Jane, Siobhan
Johanna - Josie
John - Johannes, Joannes, Ioannes, Sean (Irish), Owen (Scottish)
Jugge - Judith
Lack, Lacky - Laughlin
Linda - Lynda, Lyn, Lynn, Lynne, Lindy, Lindi
Louie - Lucinda, Ludovicus
Margaret - Margery, Margo, Marguerite, Marjorie, Magan, Rita, Madge, Maggie, Maisie, May, Meg, Peg, Peggy, Margaron
Mary - Maria, Maura, Maire, Maureen (younger Maura)
Mundy - Redmond
Nancy, Nanny, Nano - Anne
Nappy - Penelope
Petrus - Peter
Polly, Molly - Mary
Rody, Rory - Roderick
Shibby - Isabella
Sia - Cecilia
Saoirse - pronounced Sersha - female for George
Tatty - Clotworthy
Thaddeus - Timothy
Names ending in 'een' mean young or small
Names with og with an accent over o means young; Seanog = young Sean
Link to a website with more nicknames.
Latin translations:
Jacobum or Jacobus = James
Gulielma = William
Brigidam = Bridget
IrelandXO Insight - Old Irish boys' names & aliases
ENGLISH NAMES AND IRISH EQUIVALENTS
Girls names:
Barbara – Gormladh (pronounced "Gurm-la").
Elizabeth – Sibeal (pronounced "Sybil").
Grace – Gráinne (pronounced "Grawn-ya").
Jane/Janet – Sinéad (pronounced "Shin-ade").
Joan/Joanna – Siobhán (pronounced "Shiv-awn").
Margaret – Mairéad (pronounced "Mor-ade").
Patricia - Pat, Patsy, Tricia, Trish, Pádraigín and Patrice
Boys names:
Charles – Cathal (pronounced "Caw-hal"). This also gives us the surname Cahill.
Daniel – Domhnall/Dónal (pronounced "Dough-nal"). This also gives us the surnames McDonnell and O'Donnell. Think of "Daniel O'Donnell".
Dermot – Diarmuid (pronounced "dear-mid").
James – Séamus (pronounced "Shay-mus") - often Shay for short.
Patrick - Pádraig, Páraic, Paudie, Padge, Pauric, Podge, Pat, Paddy, Patsy and Pa
Terrence/Terry – Turlough (pronounced "Tur-lock")
Timothy – Tadhg (pronounced "tie-g").
IrelandXO Insight - Old Irish first names and aliases