Fiat money is a government-issued currency that is not backed by a physical commodity, such as gold or silver, but rather by the government that issued it. It usually requires fiat exchanged at a CEX or through local means such as Bitcoin ATMs to be able to purchase cryptocurrency with fiat currency.
Slippage refers to the difference between the expected price of a trade and the price at which the trade is executed. Slippage can occur at any time but is most prevalent during periods of higher volatility when market orders are used. It can also occur when a large order is executed but there isn't enough volume at the chosen price to maintain the current bid/ask spread.
Timing risk is the speculation that an investor enters into when trying to buy or sell an asset based on future price predictions. Timing risk explains the potential for missing out on beneficial movements in price due to an error in timing.