[{"Bold_text": "verb (used with object)", "List Items": ["to make hard hardor harder:to harden steel.Synonyms: ossify , petrify , indurate , solidify Antonyms: soften", "to make pitiless or unfeeling:to harden one's heart.", "to make rigid or unyielding; stiffen:The rigors of poverty hardened his personality.", "to strengthen or confirm, especially with reference to character, intentions, feelings, etc.; reinforce.Synonyms: nerve , brace , steel , fortify Antonyms: weaken", "to make hardy, robust, or capable of endurance; toughen.", "Military.to reinforce the structure of (a military or strategic installation) to protect it from nuclear bombardment."]}, {"Bold_text": "verb (used without object)", "List Items": ["to become hard or harder.", "to become pitiless or unfeeling.", "to become rigid or unyielding; stiffen:His personality hardened over the years.", "to become confirmed or strengthened:His resistance hardened.", "to become inured or toughened:The troops hardened under constant fire.", "Commerce.(of a market, prices, etc.)to cease to fluctuate; firm:When the speculators withdrew from the market, the prices hardened.to rise higher.", "to cease to fluctuate; firm:When the speculators withdrew from the market, the prices hardened.", "to rise higher."]}, {"Bold_text": "noun", "List Items": ["Sir Arthur,1865–1940,English biochemist: Nobel Prize 1929."]}]