In other words, beginning with ign-

• ign- prefix. (Latin) Fire.
• ignatia, noun. Dried ripe seeds of the plant Strychnos ignatia (St. Ignatius’s Bean), used as a homeopathic remedy.
• igneous, adjective. (Geology) Produced under conditions involving intense heat; for example, rocks of volcanic origin or rocks crystallized from molten magma.
• ignescent, adjective. Emitting sparks of fire (as certain stones when struck with steel); bursting into flame.
• ignify, verb. (rare) To form into fire; to turn into fire.
• ignimbrite, noun. (Petrology) A fine-grained volcanic rock consisting mainly of welded shards of feldspar and quartz.
• ignition, noun. The act or fact of igniting (i.e., setting on fire); a means or device for igniting.
• ignoble, adjective. Of low character, base; of low quality; inferior; not noble, of humble descent or rank.
• ignominious, adjective. Marked by or attended with ignominy (i.e., disgrace, shame, contempt); contemptible.
• ignoramus, noun. An extremely ignorant person; simpleton,
• ignorant, adjective. Lacking in knowledge or training; unlearned; lacking knowledge or information as to a particular subject or fact; uninformed.
• ignore, verb. To refrain from noticing or recognizing; overlook, neglect.