diff --git a/src/twomartens/masterthesis/definitions.py b/src/twomartens/masterthesis/definitions.py
index 0c16d76..83a13d3 100644
--- a/src/twomartens/masterthesis/definitions.py
+++ b/src/twomartens/masterthesis/definitions.py
@@ -19,11 +19,12 @@ Provides defined constants.
 
 Attributes:
     COCO_TO_WNID: specifies a mapping from COCO ids to WordNet ids
+    WNID_TO_COCO: specifies a mapping from WordNet ids to COCO ids
 """
 
 COCO_TO_WNID = {
-    1: [],
-    2: ['04466871'],
+    1:  [],
+    2:  ['04466871'],
     25: ['02773838'],
     27: ['02773838'],
     40: ['03603722', '04591713', '02960903', '04591713', '02876657'],
@@ -50,3 +51,88 @@ COCO_TO_WNID = {
     76: ['03603722', '04522168', '02960903'],
     80: ['04453156'],
 }
+
+WNID_TO_COCO = {
+    '04466871': [2],
+    '02773838': [25, 27],
+    '03603722': [40, 76],
+    '04591713': [40, 40],
+    '02960903': [40, 76],
+    '02876657': [40],
+    '03797390': [42],
+    '03063599': [42],
+    '02880940': [46],
+    '03001627': [57],
+    '03002711': [57, 58],
+    '20000018': [57],
+    '20000024': [57],
+    '20000016': [57],
+    '20000015': [57],
+    '20000025': [57],
+    '04593077': [57],
+    '04062428': [57],
+    '03168217': [57],
+    '20000023': [57],
+    '20000026': [57],
+    '20000022': [57],
+    '03786621': [57],
+    '08647616': [57],
+    '03262932': [57],
+    '03649674': [57],
+    '04099969': [57],
+    '20000027': [57],
+    '20000020': [57],
+    '03376595': [57],
+    '02738535': [57],
+    '04373704': [57],
+    '04331277': [57],
+    '04590933': [57],
+    '20000030': [58],
+    '20000028': [58],
+    '20000029': [58],
+    '04256520': [58],
+    '03990474': [59],
+    '03956922': [59],
+    '03991062': [59],
+    '03957315': [59],
+    '20000007': [60],
+    '20000004': [60],
+    '02920259': [60],
+    '03165096': [60],
+    '03962852': [60],
+    '20000006': [60],
+    '04398951': [61],
+    '03246933': [61],
+    '20000040': [61],
+    '04061681': [61],
+    '20000038': [61],
+    '03904060': [61],
+    '03092883': [61],
+    '20000039': [61],
+    '03063968': [61],
+    '20000037': [61],
+    '20000041': [61],
+    '03620967': [61],
+    '03179701': [61],
+    '04379243': [61],
+    '04446276': [62],
+    '03782190': [63, 64],
+    '03085219': [63, 64],
+    '06277280': [63],
+    '03642806': [64],
+    '03085013': [67],
+    '03261776': [68],
+    '03179910': [68],
+    '02992529': [68],
+    '04401088': [68],
+    '04330267': [70],
+    '04553920': [72],
+    '03325088': [72],
+    '03775636': [72],
+    '04559451': [72],
+    '04223580': [72],
+    '06410904': [74],
+    '03046257': [75],
+    '04522168': [76],
+    '04453156': [80]
+}